There are many existing systems that perform networked digital video recording. These systems are often comprised of readily available components. Such components often include a TCP/IP network, one or more digital video cameras and one or more storage servers. Storage servers are computer systems running software that receives video data from the video cameras and stores the video data on a storage medium such as a hard disk drive. Some digital video recording systems also use viewing application software resident on remote computers. This viewing application software may be used for viewing live or pre-recorded video data received from either the video cameras or the storage servers. The live or pre-recorded video data may be viewed in one or more viewing windows generated by the viewing application software and rendered on a computer display. The viewing application software typically provides the ability to extract pre-recorded video data from a given camera for storage in a video file. The video file may then be played back using any suitable media player, such as the Apple QuickTime™ media player.
Video files are useful since they may be used to maintain a record of significant events following the deletion of video data stored on the storage server to make way for new video data. Additionally, video files may be sent to other parties who either do not have viewing application software installed, or do not have sufficient privileges to access a storage server. For example, video data extracted and stored in a video file (e.g., a QuickTime™ file) in order to submit evidence of a crime to law enforcement agencies.
Additionally, some viewing application software provides the ability to view synchronised pre-recorded video data from multiple networked cameras. In one known digital video recording system, viewing application software generates a timeline showing the exact time of the video data currently being played. Clicking on the timeline allows the time of video data currently being played to be changed. The timeline also contains information about events that occurred concurrently to the video data currently being played. These events are displayed as vertical bars. Hovering the mouse over one of these vertical bars causes additional information about the event (in the form of a ‘tooltip’) to be displayed near the vertical bar.
The digital video recording systems described above suffer from the disadvantage that extracted video data (e.g., video data extracted and stored in a video file) loses information which would otherwise have been available to a user running viewing application software used to extract the video data.
Thus, a need clearly exists for a more efficient method of storing video data in a video file.